Current global usage of fresh water averages about 70% for agricultural purposes and in arid areas such as the middle east, the quantity reaches 85%. Large quantities of the water accounted for agriculture and in the production of food and fibers, is wasted due to poor water retention by sandy and marginally sandy soils. It has been estimated that sandy soil regions require from about 7 to 17 times more water than is actually used to produce maximum food and fiber yields. Similarly, it has been estimated that sandy soil regions retain less than 10% of rainfall in the root zone between the soil surface and 60-70 cm (cm) below the soil surface, with the remaining water draining beyond most root configurations, leaching most plant nutrients and pesticides to depths beyond the roots of food and forage crops.
Soil texture can provide a controlling influence on groundwater quality and quantity. For instance, because precipitation migrates through soil prior to recharging groundwater or outcropping to surface water bodies, water quality is linked to soil quality. Similarly, many issues related to water usage and conservation are linked to water use efficiency in agriculture and to emerging industrial activities in the developing world.
Large areas of land, including more than 23 billion acres of highly permeable soils are located in arid and semi-arid areas of the world. Due to the porosity of the soil, insufficient quantities of water and/or nutrients are retained in the root zones of most plants to maintain sustainable agriculture and grazing landscapes. These water and nutrient deficiencies can be caused by various conditions such as coarse soil texture, poor soil structure, lack of precipitation, or limited available irrigation. Water deficits reduce agricultural efficiency and food production and can have detrimental results, especially when affecting underdeveloped parts of the world. Sub-Saharan Africa, for example, experiences some of the most unfavorable climate inconsistencies and insufficient soil water availability, shortening its growing season and limiting its agricultural production.
As the population of the world continues to grow, the need for using this marginal land for agricultural purposes becomes more pressing. In many areas, good agricultural land is becoming sufficiently scarce so as to create a need for economical and easily applied methods for reclaiming sandy and other porous soils, which would otherwise lack sufficient water retention properties for sustainable agriculture. The growing world population also faces the issue of a depleting supply of high quality water. Rapid drainage of rainwater through soil requires large quantities of water for maintaining agricultural production and causes irregularities in the hydrologic cycle. Furthermore, food supplies are becoming less sufficient in feeding the growing population, creating more competition for the water needed to grow crops.
Current attempts to provide subsurface barriers have failed to address these issues. For example, asphalt barriers were developed to eliminate water percolation to depths below the root zone. However, these barriers also limit root growth through and below the subsurface soils. Additionally, during excessive rainfall, lower regions of the root zone can become saturated, resulting in root disease and death. Additionally, since the asphalt barriers limit root growth below the barrier, plants can easily become water stressed during prolonged periods between rainfall and/or supplemental irrigation activities
Yet other systems, require installing strips of plastic, at various soil depths, film or film-forming liquid, non-biological flexible membranes, installed at any desired depth below a surface, such as a soil surface.
One prior art solution in the same relative field is disclosed in United States Publication Number 2013/0209172, published Aug. 15, 2013 to Smucker. This solution faces some of the challenges described herein, as well as others that will become apparent to one skilled in the art.
Other liquid retention problems arise in the storage of water or organic chemicals in open air environments or in storage tank environments which cannot be sealed by virtue of the liquid being stored. Retaining water or organic chemicals below a surface region to mitigate evaporation losses would also be beneficial. In respect of organic chemicals, prior solutions have primarily focused on designing storage tanks in a manner that permits the requisite ventilation.
In general, these and other problems in the art relate to the issue of maintaining a liquid in a predetermined zone below a surface or to maintaining liquid within a predetermined subsurface region to mitigate liquid losses due to evaporation or to drainage of water outside of the predetermined subsurface region.